ci: treat warnings as errors

.github/workflows/unit-tests.yml

@@ -22,6 +22,7 @@ concurrency:
 
 env:
   CARGO_TERM_COLOR: always
+  RUSTFLAGS: --deny warnings
 
 jobs:
   unit-tests:

src/options/view.rs

@@ -431,6 +431,7 @@ mod test {
         &flags::NUMERIC,
     ];
 
+    #[allow(unused_macro_rules)]
     macro_rules! test {
         ($name:ident: $type:ident <- $inputs:expr; $stricts:expr => $result:expr) => {
             /// Macro that writes a test.